The thread has drifted quite far from the shore, but I have some more impressions of the Nanohone stones, and where better to put them than this thread?
Not about the 200, alas. I haven't had thinning to do. Actually, I've been honing razors, and the only time you would use a 200 stone on a razor would be if it were not actually shaped like a razor already.
The 400 is slightly more thirsty than the Shapton Glass 500 (but what is not), wears faster, and is considerably faster. It took care of some serious divots in the edge of my very-hard-steel razor in about 1/3 of the strokes that the SG500 would have needed. I was impressed.
The 1000 is surprisingly different from the others in the line. It is very thirsty, makes slurry very readily, and is a delightful playing-in-the-mud experience. I like it a lot. If you were going to buy one Nanohone, I'd suggest this one. Fast, too.
The 3000 is very different, a creamy-feeling stone that is not thirsty at all, quite decently fast. It did a great job getting some nice thin lines onto my razor bevel that I could see in my microscope, preparing me to move into JNat territory.
I'm feeling quite good about this Nanohone line, and I retract what I said about maybe selling them. I want these around.